This invention relates to lumber processing equipment, more particularly the invention relates to equipment for the automated measuring and further processing of the lumber including sawing and marking.
With rising labor costs and demands for more time and cost efficient construction, it has become desirable to construct building components and modules off-site at specialized fabrication facilities. In manufacturing wood frame walls, especially for prefabricated residential structures, there are great economies in providing automated equipment that can measure, cut, and mark the components utilized in wall frames. Where a particular wall design is repeated over and over, such automated equipment can decrease time of construction and lower costs. The economics are even greater for custom wall designs. For wood structures where the frames are constructed on site, precutting and marking of boards off-site can create a xe2x80x9ckitxe2x80x9d design minimizing necessary on site sawing and specialized labor.
Known board processing equipment that has any level of automation is mechanically complex and has limitations in capabilities. Moreover, such known equipment for marking and sawing boards requires stopping the board for each marking. Moreover, such equipment has a limited number of marking options. See, for example, U.S. Pat. No. 3,685,129 to Jureit, et. al. Said patent is hereby incorporated by reference. Moreover, known board processing equipment has not combined efficient board feeding aspects to the measuring, sawing, and printing functions.
xe2x80x9cBoardxe2x80x9d when used herein refers to elongate pieces of lumber without restriction to size including length. For example, various lengths of 1xc3x971""s, 2xc3x972""s, 2xc3x974""s, 2xc3x9710""s, etc., all are included in boards. Any lumber pieces which could be used for studs, plates, headers, and trusses are included as boards. Similarly, lengths of linear veneer laminate, oriented strand board, finger joint board, are included in the definition of the boards.
An automated board processing system process expediently handles a series of boards to measure, mark and/or saw same with optimal mechanical simplicity and efficiency.
In preferred embodiments the invention includes a transverse board conveyor, a board extrusion portion, a marking station, a sawing portion, and one or more board feeding portions, all of which are controlled by a process controller. In such, preferred embodiments, one or more stacks of boards are serially fed onto the transverse board conveyor and are conveyed in a direction transverse to the length of the boards. The boards are individually deposited into an elongate receiver of a board extrusion portion to be conveyed longitudinally. A carriage in the receiver transports the boards past an end detection station, past a marking station, and to a sawing station. The carriage has a gripping portion comprising a moveable-clamping member which in one embodiment pinches the distal end of the board (with respect to the saw station) between a wall of the receiver and the clamping member. The carriage moves down the receiver with the board clamped thereto conveying the board in a longitudinal direction to position the board in a desired position for sawing the board. The sawing station is located at a proximal end (with respect to the saw station) of the receiver with proximity sensors, such as optical sensors comprising the, end detection station also positioned at said end. A clamping station comprising a pair of gripping rollers secure the proximal end of the board adjacent the saw station for sawing. The marking station, also positioned at said end, prints desired indicia at selected positions on the board such as by an ink jet printer without physical contact of the printing mechanism with the board and while the board is moving.
Automation is provided by a process controller, such as a personal computer. The board feeding portion, the board-conveying portion, the extruding portion, the sawing portion, and the marking portion are all controlled by the process controller. The process controller handles the necessary computation for determining saw locations, printing locations, printing data, and operation of the various equipment portions. Data regarding sawing locations on boards, board-printing locations, printing indicia are all input into, calculated by, downloaded into and/or stored by the process controller. Such data may be input manually at the counsel.
As the board is conveyed down the receiver, under control of the process controller the optical sensors convey to the process controller the point at which the proximal end passes the optical sensors. An encoder or other position indicating sensor connected to the carriage drive provides the location of the carriage as the optical sensors are triggered at the end of each particular board. The process controller can then calculate the length of the board and board locations for printing or sawing. Pairs or multiple optical sensors can similarly identify the angle of the preexisting cut on the end of the board as well as the dimensions of the board. The process controller determines and controls the timing and actuation of the movement of the carriage, the gripping function, the marking station and sawing portion as the board is advanced.
A feature and advantage of particular embodiments of the invention is that the clamping, conveying, marking and sawing is accomplished with a mechanically simple configuration with a minimal number of moving parts and a minimal number of actuators and powered components. For example, the clamping of the carriage at the distal end of the board and the clamping of the distal end of the board to the receiver may be accomplished by a single actuator operating a pivoting clamping member.
Thus an advantage and feature of particular embodiments of the invention is that the gripping portion including the clamping mechanism for the distal end of the board to be sawed is mechanically simple while still reliably securing the board.
A further feature and advantage of particular embodiments of the invention is the clamping station has minimal moving parts with a first roller freely rotatable and fixed in position and a second roller freely rotatably and laterally moveable and biased toward the first roller to clamp the board to be sawn therebetween. One or both of said rollers can be tilted slightly in the direction of the board travel to assure the board is properly seated at the saw station.
A further feature and advantage of particular embodiments the invention is that the board at the sawing station is reliably and securely held down and clamped without active or powered mechanisms.
A further feature and advantage of preferred embodiments of the invention is that the board is actively clamped only at the moveable carriage. Moreover, the clamping mechanisms do not need to extend above the board being processed, rather they only engage the sides of the board. This keeps the mechanism very simple and does not require any adaptation of the clamping mechanisms for different sizes of the boards. Moreover, in preferred embodiments, the delay in gripping the distal end of the board until after the proximal end has passed the end detection station assures the distal end is properly against the carriage. Moreover, the gripped distal end of the board provides optimal control over the movement of the board in both forward and backward directions.
An advantage and feature of particular embodiments of the invention is that the overall system has an optimally small footprint to minimize the floor space needed for the system.
A further advantage and feature of particular embodiments of the invention is that the length of boards may be determined or verified before the board is cut or marked.
A further advantage and feature of particular embodiments of the invention is that marking of lumber for future operations is accomplished reliably and accurately without stopping, slowing, or otherwise interfering with the travel of the board.
Moreover, the gripped distal end provides optimal control over the movement of the board in both forward and a backward directions.
A further advantage and feature of particular embodiments of the invention is that board markings can be infinitely varied in size, positioning and in the particular indicia utilized.
A further advantage and feature of particular embodiments of the invention is that there is no direct contact between the marking mechanism and the board and thus no interference with the travel of the board and no wear or other stress on the marking mechanism.
A further advantage and feature of particular embodiments of the invention is that marking and sawing of the boards is accomplished in essentially the same operation minimizing the time and equipment needed for these operations if performed on distinct pieces of equipment.